The present invention relates generally to wireless communications devices, and particularly to wireless communications devices having session based text or video messaging capabilities.
Instant messaging allows users to send and receive text messages by establishing communications sessions. Historically, users have sent and received instant messages using a personal computer connected to the Internet. Given its popularity, however, it is no surprise that instant messaging has now moved to the realm of the wireless communications network. Users in both worlds can now send and receive text messages; however, the concept of “presence” was modified slightly for mobile users.
“Presence” is a service that allows a user to inform other users about his reachability, availability, and willingness to communicate. The presence service indicates a user's presence status, for example, whether users are on-line, off-line, idle, busy, or on the phone. In addition, the presence service may provide information about a user's means and capabilities to send and receive some types of data such as video, audio, and text messages. A user who wishes to be kept informed of another user's presence status is referred to as a “watcher.” A user who informs the watcher of his or her presence status is referred to as a “presentity.”
Typically, watchers who wish to be kept informed of a particular presentity's status subscribe to a presence server in a network. In some systems that use the Session Initiation Protocol (SIP) for signaling, watchers may send a SUBSCRIBE message as is known in the art. The subscription acts as a standing request to notify the watcher of the presentity's current presence status (e.g., on-line to off-line) and when it changes. When the presentity's status changes, the presentity notifies the presence server. The presence server than publishes the status change to the watcher.
However, presence under the current paradigm does not always accurately indicate the presence status of a mobile user. More particularly, current presence services indicate a person's ability to respond to received messages. This is because presence under the current paradigm is based on the generally “fixed” physical location of the computer. A user who is logged on to a desktop computer and able to respond to messages, for example, may be indicated as being “Active,” or “Online,” while a user who is logged off may be indicated as being “Offline.” Still, other presence information lets users know which people are “Inactive,” or “Idle” (i.e., away from the computer keyboard). Mobile users, however, generally do not remain in “fixed” positions and are not tethered to a particular desktop computer. Thus, a mobile user's status or ability to respond is implied by the location and/or an activity of the mobile user.
To date, some modifications to the presence service have been made to better comport with the specific needs of mobile users. However, not all needs have been addressed.